I have the same problem
I had my machine repaired by apple (2.6 Ghz Intel Core 2 Duo Mac Book Pro running 10.5.6)
I then had to reinstall all my apps but cannot get Vectorworks 2009 SP 1 & 2 past the XML library message
VW worked fine before the repair. I am suspecting that it is related to the fact that I am probably installing it over a later version of the system software.
What I mean is that when I first installed VW I would have been on the current system i.e. prior to 10.5.6 now I have reinstalled the system and then got it up to date then started to install my applications including VW.
If this is correct I could start again but not update the system until after installing VW. If this sounds like a viable plan I would be interested to know.
Note I can install VW 2009 SP1 & 2 on an older machine with no problem and I have tried the new user suggestion.
